Continuous onsite-manufactured pipe

ABSTRACT

Method and article of manufacture are disclosed for onsite-manufacturing of any length, any shape, size, and any thickness pipe. Sheets of fabrics saturated with resin may be wrapped around desired shape mandrels, cured, and removed to form such pipes onsite. Cured laminated sheets of resin-saturated fabrics may be wrapped around to also form onsite manufactured pipes. Disclosed pipes eliminate almost all weaknesses of plastic, metal and concrete pipes and noticeably reduce costs of transportation as well as manufacturing. One of the advantages of the disclosed pipes is that they have few joints, limiting the leakage and other problems associated with joints in ordinary pipes.

CROSS-REFERENCE(S) TO RELATED APPLICATION(S)

This application claims the benefit of the priority date of the U.S.Provisional Patent Applications No. 61/633,685, filed on Feb. 16, 2012,titled “Long Continuous Onsite-Manufactured Pipe”.

TECHNICAL FIELD

This application relates generally to construction. More specifically,this application relates to a method and apparatus for on-sitemanufacturing of pipes of any length and any size and shape.

BACKGROUND

For centuries pipes have been used to carry fluids, gases, etc. inwater, wastewater, gas, oil, mining and other industries. All thesepipes, especially for large projects, are manufactured in factories inpieces that are typically 16-24 feet long and are shipped by trailers ortrains to the jobsite for installation. During the installation process,the short pieces are joined together to create a longer pipe. In buriedpipes, a trench must be excavated to place the pipe below ground.

There are several shortcomings with such a system. (1) The shipping isvery costly as often these pipes are bulky and hollow; in fact thetrucks carry a lot of “empty” and unused space enclosed within thehollow pipes. When larger diameter pipes (4-ft and larger) aretransported only a few pieces of pipe can be placed on a truck bed whichadds tremendous expense to the project. (2) The pipe sections are veryheavy and require heavy lifting equipment onsite to remove the pipe fromthe truck bed and position it in the trench. (3) The joints in all pipesare the major source of leakage; there are numerous organizations suchas ASCE and EPA that provide statistics on the continuous waste ofwater, and leakage of pollutants such as sewer, gas, oil, etc., andwaste of other resources because of leakage through the pipe jointswhile contaminating the surrounding areas. The joints are also a pointwhere roots can penetrate sewer pipes, for example, causing clogging ofsuch pipes. (4) When steel or concrete pipes are used, the steel inthese pipes corrodes over time, causing failure of the pipes which inturn incur major repair or replacement costs. (5) In industries such asgas and oil, where steel pipes are frequently used, cathodic protectionsystems must be installed to protect these pipes against corrosion.These systems require continuous monitoring and replacement ofcomponents to ensure proper operation. These costs become significantover the life of the pipe. (6) The electrical current that passesthrough gas or oil pipes, for example, can become stray and acceleratecorrosion of other nearby metallic structures. This, for example, is aconcern of the electrical utilities where their steel poles corrode at amuch faster rate due to these stray currents. Depending on the strengthof the current, a pipe may adversely affect a utility pole that ishundred feet or more away from the pipe.

The construction of currently used pipes that are made of steel,concrete or plastics (e.g. PVC, fiberglass, etc.) requires majormanufacturing equipments that must be housed in a factory and which arenot portable. For example, the equipments needed to melt the steel orroll a steel sheet into a cylindrical pipe is very bulky and heavy.Likewise, mixing of concrete and casting it in a mold to produce aconcrete pipe is very difficult and does not lend itself to onsitemanufacturing. Even in the case of fiberglass or other plastic pipes,their manufacturing requires a great deal of heat and spinning equipment(since many of these pipes are cast in centrifugal rotating machines),which require large spaces and facilities and are generally not portableto job sites. Therefore, such pipes can never be constructed onsite onan “as-needed” basis.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings, when considered in connection with the followingdescription, are presented for the purpose of facilitating anunderstanding of the subject matter sought to be protected.

FIG. 1 shows an example of repairing a deteriorated pipe using onsitemanufactured pipe;

FIG. 2 shows an example method of manufacturing an FRP-and-Resin pipe;and

FIG. 3 shows an example cross-section of a disclosed pipe.

FIG. 4 shows relative stiffness of same pipe materials with differentthickness Spacer layers.

FIG. 5 shows an example process of manufacturing a pipe.

DETAILED DESCRIPTION

While the present disclosure is described with reference to severalillustrative embodiments described herein, it should be clear that thepresent disclosure should not be limited to such embodiments. Therefore,the description of the embodiments provided herein is illustrative ofthe present disclosure and should not limit the scope of the disclosureas claimed.

Briefly described, methods and articles of manufacture are disclosed forreplacing, repairing, reinforcing existing pipes, andonsite-manufacturing of new pipes of various shapes and sizes andlengths, with minimum cost, effort, and time. These methods and articlesof manufacture can replace an entire pipe or a part or a segment of apipe or repair a pipe or a structural member from outside, inside, orboth. FIG. 1 shows an example of repairing a deteriorated pipe 110 usingonsite manufactured pipes 120 and 130. FIG. 1 depicts the possibility ofusing onsite manufactured pipe 120 inside the damaged pipe 110 or onsitemanufactured pipe 130 on the outside of the damaged pipe 110, or both.

Pipe manufacturing and installation, and also pipe repair andreplacement can be expensive, cumbersome, and time consuming. Pipes canget damaged due to a variety of factors, such as earthquakes,overloading, weight of traffic, wear and tear, corrosion, explosions,and the like. If damage does occur to a pipe, a cost-effective andspeedy method of repair is clearly desirable. While pipe repair andreplacement are emphasized in this disclosure, other structures, damagedor undamaged, can benefit from the disclosed methods and apparatus. Thedisclosed onsite manufactured pipes can even be used as concretemolding, such as for bridge columns, and can be left around the concretestructural elements for protection.

In various embodiments, the pipe is constructed from fiber-reinforcedmaterial, such as Fiber Reinforced Polymer (FRP) to give the pipe moreresistance against various types of loading, such as blast loading.Those skilled in the art will appreciate that many types ofreinforcement fibers may be used for manufacturing the disclosed pipesincluding polymer, fiberglass, metal, cotton, other natural fibers, andthe like. The sheet materials used in manufacturing these pipes mayinclude fabrics made with fibers such as glass, carbon, Kevlar, Nomex,aluminum, and the like, some saturated with a polymer such as polyester,vinyl ester, or epoxy for added strength, wear resistance, andresilience. The fibers within a reinforcement sheet may be aligned inone direction, in cross directions, randomly oriented, or in curvedsections to provide various mechanical properties, such as tearingtendency and differential tensile strength along different directions,among others. Other multi-dimensionally woven materials, known asmulti-axial fabrics, can also be used in the manufacture of these pipes.Such materials are currently obtainable from companies such as FiberMaterials, Inc., 5 Morin Street, Biddeford, Me.

In this disclosure, the word “fiber” is used for any sheet of materialthe strength of which, at least partially and at least in one direction,depends on fibers of some kind, whether the fibers are woven, stitched,or held together by other means such as glue.

The reinforcement layers that form the onsite manufactured pipes may belaminated in the field using epoxy, various glues, or similar adhesivesto create a laminated composite that is stiffer than the sum of theindividual reinforcement layers. Different reinforcement layers may usesheets with fibers oriented in different directions, such as orthogonaldirections, with respect to other sheets to further reinforce thelaminated composite. Other materials, as will be described below, suchas foams, honeycomb sheets or multi-axial fabrics, may be included inthe laminate layers to achieve different desirable mechanical,structural, and other characteristics. Those skilled in the art willrecognize that many other types of reinforcement layers such ashoneycomb, hollow structures, or laminated structures are possiblewithout departing from the spirit of the present disclosures.

The interior layers of the fabric can provide abrasion and chemicalresistance, for example when the pipe is carrying chemicals andslurry-type materials that could result in excessive wear on the surfaceof the pipe. These same interior layers can also be designed to resistinternal pressure of the pipe.

Example materials for building pipes and their reinforcement layers andsheets are “FRP” and resin,” and in some embodiments spacer sheets, allof which are very light-weight and can be delivered to the job site oreven stored on a mobile platform such as a trailer or a truck that canmove along the trench where the pipe is being made or repaired.

The following is an example method of manufacturing a pipe, which isdepicted in FIG. 2. Some of the disclosed steps may be totallyeliminated or reordered, as a user may decide.

1) Provide a mold or a mandrel 250 that represents the desired size andshape of the pipe being manufactured. For example, an already availablecylindrical corrugated metal pipe may be used as mandrel 250. Thismandrel can also be designed to be “collapsible,” so once the pipe isconstructed the mandrel is collapsed to a smaller size to alloweffortless removal of the finished pipe and easy transportation of themandrel. Those skilled in the art will realize that the cross-section ofthe mandrels and manufactured pipes need not be circular and can haveany desired geometric shape, such as oval, square or polygon;

2) Apply a release agent to the mandrel 250 or wrap a plastic/nylonsheet 260 around the mandrel 250, or use any other means, to allow easyremoval of the finished pipe 270 from the mandrel 250;

3) Saturate an FRP fabric with Resin;

4) Wrap any desired number of layers of saturated FRP fabric around themandrel 250, over plastic/nylon sheet 260;

5) If desired, wrap any number of spacer layers such as honeycomb ormulti-axial fabric type layers between any number of FRP layers. Asbriefly mentioned above, spacers are optional layers for achievingdifferent desirable mechanical, structural, and other characteristics byutilizing, for example, hollow cells on a surface, and/or using wrinkledor corrugated material sheets, creating a largely hollow core layer,which may be filled with resin or other reinforcing material to increaseits stiffness and strength. A spacer may be foam that is sprayed in thefield or pre-formed into sheets similar to NexCore produced by Milliken(Spartanburg, S.C.). A spacer may even be an already manufacturedlaminated sheet of FRP layers. If the spacer sheet is not long enough togo around the mandrel 250 in one piece, one may use multiple sheets. Ifthe spacer material is thick and/or stiff, the spacer may be scored toallow it to bend to fit around the curvature of the mandrel 250. Theends of the spacer sheet(s) can be trimmed at an angle for betterbutt-joints. For manufacturing a long pipe, in some embodiments a fewinches of at least one FRP layer is left exposed at one or both ends ofeach pipe section to be used for joining the pipe sections together;

6) Allow the assembly to at least partially cure. Cure time may bereduced for example by exposure to air, heat, or UV light for someresins. The full curing of the pipe may continue for a while afterremoval from the mandrel until the pipe reaches its full strength;

7) Remove the manufactured pipe section 270 from the mandrel 250 bysliding it over the release agent or the plastic/nylon sheet 260; and

8) Butt-joint molded pipe sections 270 using the exposed FRP's and/orwrapping additional resin-saturated FPR bands around the butt-joints.

Those skilled in the art will recognize that, as an alternative methodof manufacturing these pipes, some of the disclosed steps may also beused to manufacture flat or merely curved laminated sheets, and thatsuch flat and curved laminated sheets can be later wrapped around andsealed to form a pipe onsite. This alternative makes it possible tomanufacture laminated sheets away from the job-site and easily andeconomically transport them to the job-site, where they can be readilyformed into pipes. For example, a square or rectangular laminated sheetmay be wrapped around to bring two of its opposite sides together,forming a seam that is subsequently covered by one or more straps ofresin-saturated fabric. In another exemplary embodiment the oppositeends may be glued together in an overlapping arrangement.

In yet another exemplary embodiment the fabric and spacer can be dry orpartially saturated with resin and wrapped around the mandrel, then theentire assembly is sealed in an air-tight plastic bag and resin isintroduced through vacuum suction to saturate the entire pipe assembly;this technique is commonly referred to as “vacuum molding” in the FRPindustry.

In cases where the manufactured pipe is being inserted into a damagedhost pipe to replace the function of a part of the damaged pipe, atleast a part of the outside surface of the manufactured pipe such as itsends may be roughed, for example by sanding or by sand blasting or byspraying a mixture of sand and Resin, to enhance bonding of the pipe tothe host pipe in the field.

The mandrel 250 can be mounted on wheels as a moving station that cantravel alongside the trench. The above procedure allows the light-weightconstituent materials of the pipe, namely FRP, resin and the optionalspacer layer to be delivered to the crew while the pipe is constructedand placed. If desired, the raw materials can be placed on the samemoving platform as the mandrel 250 or on a separate moving platformadjacent to the mandrel platform for higher productivity.

According to the described embodiments, it is possible to build pipes ofunlimited lengths without any joints. However, periodically along thelength of the pipe, joints may be necessary based on otherconsiderations. Pipe joints of different kinds are well known in theindustry.

Another advantage of the disclosed pipe is that it can be easily cut andspliced in the field. Splicing of the pipe will later require joints toconnect the splice, where the above-mentioned joining systems can beused. Moreover, externally wrapped FRP bands can also provide aleak-proof and strong joint. Alternatively, a larger size pipe ofsimilar construction disclosed here can be built and cut into 1-ft longslices; these slices can serve as coupling sleeves that would slip overthe ends of adjoining pipes (about 6 inches on each pipe); the smallannular space between the original pipe and the coupling sleeve can besealed with a rubber gasket or a hydrophilic seal that would expandafter exposure to water to create a compression seal between thecoupling sleeve and the pipe. If the pipe diameter is large enough toallow man entry, the joint can be made internally with FRP, or clampssuch as Weko Seal and/or other similar products that are readilyavailable.

The disclosed pipes are flexible enough to accommodate small radii ofcurvature as most pipes do. However, if an abrupt change of angle isneeded, it may require a special mandrel for constructing a pipe with aparticular shape or angle. Alternatively, a joint may be introduced atsuch locations and an especially-made curved pipe can be used tocomplete the change of direction of the pipe.

The materials including resins used in the construction of the disclosedpipes may be selected from a family of environmentally safe products sothat the finished pipe is safe for potable water. QuakeWrap, Inc.(Tucson, Ariz.), for example, provides such fibers and resins that meetthe NSF-61 industry standards for potable water.

The disclosed pipes are extremely light and very strong. For example,these pipes weigh approximately 1 pound per square foot compared to afiberglass pipe manufactured by Hobas Pipe USA (Houston, Tex.) thatweighs over 16 pounds per square foot. While all components of the pipe(for example, FRP, resin, and spacer) work together to provide thestiffness and resistance to external loads (e.g. soil, traffic, impact,blast, etc.), the internal pressure rating of the pipe is primarilydependent on the interior FRP layer(s). A typical FRP layer is less than0.05 inch thick; therefore, one may significantly increase the internalpressure rating of a pipe by adding one or more layers of FRP to theinterior surface of the pipe, which will only cause a tiny increase inthe pipe wall thickness and the weight of the pipe while increasing thepipe strength significantly.

FIG. 3 shows an example cross-section of a disclosed pipe 300. To bettermaintain its cross-sectional integrity and withstand different kinds ofexternal loads such as the deadweight of a road and the live weight ofcars and trucks passing over the road, the pipe wall needs to be thick.However, material strength of the pipe wall need not be uniformthroughout the wall thickness 340 since the major portion of the wallstresses under an external load is generated within the outer layer 310and inner layer 330 of the pipe wall. Placing a Spacer 320 between theouter layer 310 and inner layer 330 of the pipe wall closely resemblesan I-beam web between the two I-beam flanges. The thicker the Spacer320, the less stress is created within the outer layer 310 and innerlayer 330 of the pipe wall. Additionally, the inner layer 330 resiststhe internal pressure of the pipe and the outer layer 310 providesprotection against corrosion from soil or UV light, etc. In someembodiments the outer layer 310 and inner layer 330 of the pipe wall aredesigned to carry all or most of the stresses caused by the externalloads, while the Spacer layer may experience some radial stress.

FIG. 4 shows an example table of relative stiffness of same pipematerials with varying thickness Spacer layers. FIG. 4A sets two layersof saturated fabric, without any Spacer, to be the baseline forstiffness comparison. In FIG. 4B, a layer of Spacer is added between thetwo layers of saturated fabric such that the combination is twice asthick as the two saturated layers of fabric. Even without taking intoaccount the stiffness of the Spacer, the resulting stiffness is seven(7) times the stiffness of the two layers of saturated fabric alone. InFIG. 4C, the thickness of the Spacer layer is twice as the thickness ofthe Spacer layer in FIG. 4B; however, the resulting relative stiffnessis thirty seven (37) times that of FIG. 4A. As seen from the same table,the increase in weight, as a result of adding Spacer layers, is almostnegligible.

FIG. 5 shows an example process of manufacturing a pipe using resinsaturated FRP layers. Process 500 proceeds to block 510 where a mold ora mandrel of desired length and cross-section is provided. Readilyavailable products, such as pipes, whose outside dimensions fulfill theuser's requirements, can be adopted to operate as a mandrel. The processproceeds to block 520. At block 520, a release agent is applied to or aplastic/nylon sheet is wrapped around the mandrel, or any other means,to allow easy removal of the finished pipe from the mandrel. The processproceeds to block 530. At block 530, wrap any desired number ofresin-saturated FRP layers around the mandrel, over plastic/nylon sheet.At block 540, if desired, wrap any number of spacer layers such ashoneycomb, foam or multi-axial fabric type layers between any number FRPlayers. Spacers are optional layers for achieving different desirablemechanical, structural, and other characteristics. The process proceedsto block 550. At block 550, allow the assembly to at least partiallycure. The process proceeds to block 560. At block 560, remove themanufactured pipe section from the mandrel by sliding it over therelease agent or the plastic/nylon sheet or partially collapse themandrel, if collapsible mandrel is used, to remove the manufactured pipesection. The process proceeds to block 570. At block 570, butt-jointmolded pipe sections. The process proceeds to block 580, at which stepthe process ends.

The above manufacturing process lends itself well to automation. Asanother embodiment, a mobile platform can be constructed that will housethe raw materials (e.g., resin, FRP, spacer), the mandrel, and thefabrication machinery. The equipment can include moving arms that willpick up the raw materials and apply them around the mandrel and cure theresin. Certain changes in the procedure simplify the process for therobot without adversely affecting the quality of the finished pipe. Forexample, it may be easier for a robot to apply a film of resin (like apaint spray), apply the dry FRP fabric and spray more Resin on top ofthe dry fabric to saturate it. Robots can significantly increase qualityof the finished product and the production rate. At the same time thecost of a pipe manufactured with such robots can be much lower than ahand-made pipe. In some embodiments a combination of man and robots maybe employed to manufacture the disclosed pipes. For example, a workermay provide and wrap the Spacer around the mandrel while a robot appliesthe Resin and the FRP layers.

Changes can be made to the claimed invention in light of the aboveDetailed Description. While the above description details certainembodiments of the invention and describes the best mode contemplated,no matter how detailed the above appears in text, the claimed inventioncan be practiced in many ways. Details of the system may varyconsiderably in its implementation details, while still beingencompassed by the claimed invention disclosed herein.

Particular terminology used when describing certain features or aspectsof the disclosure should not be taken to imply that the terminology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the disclosure with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the claimed invention to the specificembodiments disclosed in the specification, unless the above DetailedDescription section explicitly defines such terms.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to inventions containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations).

Furthermore, in those instances where a convention analogous to “atleast one of A, B, and C, etc.” is used, in general such a constructionis intended in the sense one having skill in the art would understandthe convention (e.g., “a system having at least one of A, B, and C”would include but not be limited to systems that have A alone, B alone,C alone, A and B together, A and C together, B and C together, and/or A,B, and C together, etc.). In those instances where a conventionanalogous to “at least one of A, B, or C, etc.” is used, in general sucha construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, or C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.”

The above specification, examples, and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended. While the present disclosurehas been described in connection with what is considered the mostpractical and preferred embodiment, it is understood that thisdisclosure is not limited to the disclosed embodiments, but is intendedto cover various arrangements included within the spirit and scope ofthe broadest interpretation so as to encompass all such modificationsand equivalent arrangements.

What is claimed is:
 1. A method of manufacturing a pipe of any length,the method comprising: wrapping a first desired number ofresin-saturated fabric layers around a mandrel; placing at least onespacer layer over the first wrapped layers; wrapping a second desirednumber of resin-saturated fabric layers over the at least one spacerlayer; curing, at least partially, the resin-saturated first or secondwrapped layers, or both wrapped layers, to form a pipe segment; removingthe pipe segment from the mandrel; and connecting two or more removedpipe segments to each other end to end.
 2. The method of claim 1,further comprising wrapping a layer of bond-inhibiting material over themandrel before wrapping the resin-saturated fabric layers around themandrel.
 3. The method of claim 1, further comprising partly removingthe pipe segment from the mandrel such that a portion of a wrappedfabric remains on the mandrel to be joined with another pipe segmentsubsequently made on the mandrel.
 4. The method of claim 1, wherein theresin is applied to the fabric before and/or after the fabric is wound.5. The method of claim 1, wherein the Spacer layer is not made offiber-based material.
 6. The method of claim 1, wherein the fabric is afiber-reinforced material.
 7. The method of claim 1, wherein the fabricis a Fiber Reinforced Polymer.
 8. The method of claim 1, wherein themethod is at least partially performed by a robot.
 9. A method ofmanufacturing a pipe section, the method comprising: wrapping a firstresin-saturated fabric layer around a mandrel; wrapping a spacer sheetover the first resin-saturated fabric layer; wrapping a secondresin-saturated fabric layer over the spacer sheet; curing, at leastpartially, the resin-saturated fabric to form a pipe section; andremoving, at least partially, the pipe section from the mandrel.
 10. Themethod of claim 9, further comprising wrapping a layer ofbond-inhibiting material over the mandrel before wrapping theresin-saturated fabric layers around the mandrel.
 11. The method ofclaim 9, further comprising removing the at least partially cured pipesection from the mandrel such that a portion of the pipe section remainson the mandrel to be joined with another pipe section subsequently madeon the mandrel.
 12. The method of claim 9, wherein the Resin is appliedto the fabric before and/or after the fabric is wound.
 13. The method ofclaim 9, wherein the first and the second layers are designed to carryall or most of stresses caused by an external load on the pipe sectionand wherein the Spacer sheet may experience some radial stress.
 14. Themethod of claim 9, wherein the fabric is a fiber-reinforced material, aFiber Reinforced Polymer, or a multi-directional woven fabric.
 15. Themethod of claim 9, wherein the Spacer sheet has properties differentfrom the resin-saturated fabric layers.
 16. The method of claim 9,wherein curing is done with light, heat, a liquid, or a combinationthereof.
 17. A method of manufacturing a pipe section, the methodcomprising: spreading any desired number of resin-saturated fabriclayers on top of each other on a preferred surface to form a firstlaminated composite sheet; spreading any desired number ofresin-saturated fabric layers on top of each other on the same oranother preferred surface to form a second laminated composite sheet;curing, at least partially, the first and the second laminated compositesheets; wrapping-around the first laminated composite sheet to bring twoedges of the first laminated composite sheet together; butt-jointing oroverlapping the two edges of the first laminated composite sheet andpermanently attaching the two edges together; placing a spacer layerover the first wrapped composite sheet; wrapping-around the secondlaminated composite sheet over the spacer layer to bring two edges ofthe second laminated composite sheet together; butt-jointing oroverlapping the two edges of the second laminated composite sheet andpermanently attaching the two edges together to complete the pipesection.
 18. The method of claim 17, wherein the laminated compositesheets are manufactured offsite and the rest of the process is performedonsite.
 19. The method of claim 17, wherein the preferred surface is aflat or a curved surface.
 20. The method of claim 17, wherein thebutt-joint is covered with one or more straps of resin-saturated fabric.